The present invention relates to large stator bars that are used in power and industrial generators, handling these bars before they are installed in a stator, and fitting header clips to the bars during assembly.
Stator bars are typically large, long and heavy, e.g., 35 feet long and hundreds of pounds (lbs.). The bars are generally straight and extend the length of a stator. When seated in a stator, the straight sections of the stator bars form a cylindrical array around a rotor. The ends of the stator bars extend axially from opposite ends of the stator. The end portion of the stator bars extend from the stator and are curved to form end turns. The ends of stator bars are connected through copper or stainless steel fittings and water-cooled connections to form continuous hydraulic winding circuits.
Each water-cooled stator bar comprises an array of small rectangular solid and hollow copper strands. The array of copper strands in each bar are generally arranged in a rectangular bundle. The hollow strands each have an internal duct for conducting coolant through the bar. The ends of the bars are each connected to a hydraulic header clip.
The hydraulic header clip serves as an electrical and a cooling flow connection for the armature winding bar. The hydraulic header clip is a hollow connector that includes an enclosed chamber for ingress or egress of a cooling liquid, typically deionized water. At one open end, the clip encloses the ends of the copper strands of the armature winding bar.
A braze alloy bonds the end sections of the strands to each other and to the hydraulic header clip. The ends of the solid and hollow strands are brazed to a hydraulic header clip fitted to the end of the stator bar. Holding the assembly of strands and header clip together during the braze process is difficult. There is a long felt need for a tool to assist in fitting the hydraulic header clip to the end of a stator bar.